JPH0330862B2 - - Google Patents

Description

Detailed Description of the Invention [Technical Field] The present invention provides a method for controlling image formation using a plurality of control means including a memory storing a control program.
The present invention relates to image forming apparatuses such as copying machines.

[Prior Art] Conventionally, in this type of image forming apparatus, control data was transferred from one control means to the other control means only when necessary. In this case, one of the control means may be abnormal and control data may not be transferred, making accurate control impossible. Furthermore, it is not possible to determine that the other party's control means is abnormal and the control continues unilaterally, which is very inconvenient.

[Object of the Invention] An object of the present invention is to provide an image forming apparatus that eliminates the drawbacks of the prior art as described above.

More specifically, an input means for inputting image processing conditions, a process processing means for executing image formation, a first control means including a memory storing a control program for controlling the operation of the process processing means, a second control means including a memory storing a control program for controlling the first control means based on the image processing conditions input from the input means, and the first control means controls the second control means based on the image processing conditions input from the input means. The first control means includes an abnormal state of the process processing means.
The second control means transfers a second plurality of control data indicating the image processing conditions to the first control means, and the second control means transfers a second plurality of control data indicating the image processing conditions to the first control means. In order to repeatedly transfer data, a transfer request signal is repeatedly output from one of the first and second control means to the other at a predetermined period, and the other control means receives the transfer request signal within a predetermined time. It is an object of the present invention to provide an image forming apparatus characterized in that when it is detected that the next transfer request signal is not outputted, it is determined that there is an abnormality in one of the control means, and the abnormality processing is performed.

With this configuration, it is possible to detect the state of the other party's control means while transferring control data without providing a special abnormality detection circuit. Furthermore, even if there is an error in the control data due to noise etc.
By repeating transmission, errors can be corrected immediately.

[Embodiment] FIG. 1 is a sectional view of a copying machine to which the present invention can be applied, and its structure and operation will be explained.

The surface of the drum 1 is made of a three-layer seamless photoconductor using a CdS photoconductor, is rotatably supported on a shaft, and is rotated in the direction of the arrow by a main motor 21 activated when the copy key is turned on. Start.

When the drum 1 completes a predetermined rotation and potential control processing (preprocessing) described later, the original placed on the original platen glass 36 is illuminated by the illumination lamp 23 integrated with the first scanning mirror 24, The reflected light is reflected by the first scanning mirror 24 and the second scanning mirror 25.
is scanned. By moving the first operation mirror 24 and the second scanning mirror 25 at a speed ratio of 1:1/2, the original is scanned while the optical path length in front of the lens 30 is always kept constant.

The above reflected light image shows the lens 30 and the third mirror 2.
6. After passing through the fourth mirror 27, an image is formed on the drum 1 at the exposure section.

The drum 1 includes a pre-exposure lamp 8 and a pre-neutralizing charger 2.
The charge is removed simultaneously by the charger 3, and then the charge is corona charged (for example, +) by the primary charger 3. Then drum 1
In the exposure section, the image irradiated by the illumination lamp 23 is subjected to slit exposure.

At the same time, a secondary charger 4 performs AC or corona charge removal with a polarity opposite to that of the primary one (for example -), and then a high-contrast electrostatic latent image is formed on the drum 1 by uniform surface exposure using a full-surface exposure lamp 9. do. The electrostatic latent image on the photosensitive drum 1 is then developed by a developing roller of a developing device 7 and visualized as a toner image, and the toner image is transferred by a transfer charger 5.

Upper cassette 13 or lower cassette 14
The transfer paper inside is sent into the machine by a paper feed roller 11 or 12, and is sent in the direction of the photosensitive drum 1 by a register roller 15 with accurate timing.
The leading edge of the latent image and the leading edge of the paper can be aligned at the transfer section.

Next, while the transfer paper passes between the transfer charger 5 and the drum 1, the toner image on the drum 1 is transferred onto the transfer paper.

After the transfer is completed, the transfer paper is separated from the drum 1 by a separation belt, guided to a fixing roller 19 by a conveyor belt 17 via a paper detection sensor 16, and fixed by pressure and heat, and then transferred to a discharge roller 42.
The paper is discharged to the tray 34 via the paper detection sensor 18.

Further, 29 is a conveyance fan for reliably conveying the transfer paper. Further, after the fixing is completed, the fixing roller is cleaned by the wave 20.

After the transfer, the drum 1 continues to rotate, and a cleaning device 6 consisting of a cleaning roller and an elastic blade cleans the surface of the drum 1. The collected toner is collected in a discharge toner container 43 through a pipe 45, and then used for the next cycle. Proceed to.

FIG. 2 is a plan view of the operating section.

In the figure, 55 is a key for selecting the upper and lower cassettes, 54 is a slide lever for setting copy density, and position 5 is the standard density.
53 is a numerical key for setting the number of copies; 7
1 is a clear key for canceling the numerical value; 51 is an interrupt key for copying another number before the copying of the set number by key 53 is completed;
52 is a copy key for commanding the start of copying;
50 is a stop key for stopping the copy operation during continuous copying of the set number; 57, 58,
59 is a key for selecting the same size copy, enlarged copy, and reduced copy; 60 to 62 are indicators for displaying the selected magnification; and 60 is a key for displaying the selected reduced copy mode. , 61 displays the enlarged copy mode, and 62 displays the same size copy mode. There are five modes for enlargement: a mode for converting A size to B size, and a combination of reduction ratios of 1:0.67 and 1:0.79 and appropriate cassette selection. 72 displays the upper and lower stages of the cassette selected by the cassette selection key, and 56 displays the type of cassette loaded in the selected stage. Also, when the reduction key 59 is turned on, cassettes whose reduced size and sheet size match are displayed blinking when the selected cassette is not. At the same time, the size of the previously selected cassette is also statically displayed.

63 to 67 are warning indicators from the main body, all of which are displayed as pictograms. Reference numeral 63 is a paper feed check indicator, which lights up when copy paper is jammed inside the machine. Reference numeral 64 denotes a paper/cassette replenishment indicator, which lights up when there is no cassette in the selected cassette stand or when the paper in the cassette set in that cassette stand runs out. Reference numeral 65 denotes a discharged toner full indicator, which lights up when the container 43 is full of toner that has been used once and collected in the copying machine. Reference numeral 66 is a developer replenishment display, which lights up when the amount of developer in the developing device falls below a specified amount. 67 is a key counter confirmation indicator, which lights up when the key counter is not inserted into the socket of the main body.

70 is a weight indicator, which lights up when the power switch is turned on and the temperature of the fixing heater is lower than the specified value, and when the temperature exceeds the specified value,
The light turns off when the wait UP process is completed.

Reference numeral 68 denotes a copy number display, and when a desired number of copies is set using the dot key 53, the set number of copies is displayed in seven segments. It is possible to set 1 to 99 sheets at a time. Approximately 60 seconds have elapsed after the end of copying, or by pressing the clear key 71 or interrupt key 51, the set number of sheets and number of copies will automatically return to 01. 68 is an interrupt indicator that lights up when the interrupt key is pressed and goes out after the interrupt key is pressed.

FIG. 3-1 is a control circuit diagram of the copying machine shown in _FIG .
Q 72 is a microcomputer (hereinafter referred to as a management computer) that controls display operations and the start of copying operations, etc. _Q101 is a microcomputer (hereinafter referred to as a sequence computer) that controls the drive of the main motor, high voltage transformer, etc. for executing the copying process. ). Q ₁₀₂ is a ROM memory that stores the programs shown in the flowcharts of Figures 6-1 to 6-4 as instruction word code routines, process timing data for sequence control, the number of copy sets set by the key 53, the number of copy counts, keys 57-59
RAM memory that stores magnification data from the cassette sensor, size data from the cassette sensor, counts during emergency copying, cassette stage save data, etc.
I port, O port and I/O that control input and output
port, and clock O of clock generator 700
Reads the ROM program by reading the ROM,
CPU that processes I/O and processes programs
This is a one-chip microcomputer that has the following functions in one chip semiconductor. Q ₁₀₁ is also a one-chip microcomputer similar to Q ₁₀₂ , and the ROM memory stores programs shown in the flowcharts of FIGS. 7-1 to 7-6. Q ₁₀₃ to _{Q 105} are the five input/output ports of each computer as shown in the diagram.
This is a port for expanding to books, etc. Reference numeral 800 corresponds to the circuit of each display of the operation unit and is connected to the Q ₄ and Q ₅ ports of the management computer, and 801 corresponds to the input circuit of each key and is connected to the i ₅ port. 80
2 is a clock pulse generator for generating probe signals (digits) for scanning the key matrix 801 and the display system ₈₀₀ ;
input connected to the program interrupt port of the This pulse is frequency-divided and a repetitive signal is output from port _Q4 . Reference numeral 803 indicates two switches that detect the position of the lens system and operate according to the movement of the lens.
When set to 30-1, the signal for the same magnification is output, when set to 30-2 it is enlarged, when set to 30-3 it is reduced by 0.79, and when set to 30-4 it is the same.
Output the signal for 0.67 to Q ₁₀₅ . 804 is for detecting the size of the cassettes 13 and 14;
There are four switches in each of the upper and lower stages that are activated by the cam of the cassette when the cassette is turned on, and eight types of size data shown on the display 56 are output by combinations of on/off of three of the four switches. 806 is a switch 41 that operates when a sheet is manually inserted from above the lid of the upper cassette 13.
Then, the roller 11 is used in common for this sheet to copy one sheet. The sequence for this corresponds to the hand pointing case in FIG. 4-2. 807 is a switch for detecting the lack of toner in the developing device 7; 808;
is a switch that detects the presence or absence of a key counter (total counter for each operator) and detects contact failure, and drives the display device by a circuit not shown. 80
Reference numeral 5 denotes a lens motor circuit for setting the previous lens system to a desired position in accordance with input for changing magnification, etc., and is controlled in accordance with the selection key 59 and position detection switch 803.

809 is a line for data exchange between the computers Q ₁₀₁ and Q ₁₀₂ , and arrows correspond to data requests and data directions. 810 is a clutch circuit for turning on the registration roller; 811 is a clutch circuit for inverting the mirror system to return after exposure; 812 is a developing device motor drive circuit; 814
815 is a high voltage transformer circuit such as a primary corona, and 815 is a switch installed at the mirror reversal position for the above reversal.
816 is a switch that generates a timing signal for register feeding; 817 is a home switch that is turned on when the mirror system is at the stop position; and 818 is a drum clock consisting of a photointerrupter that generates pulses by the rotation of a disk coaxial with the main motor. A pulse generator 819 is a main motor circuit for rotating the drum, to which the clutches described above and below are connected for power. Reference numeral 820 denotes a circuit for the lamp 10 which is controlled by the timing as shown in FIG. 4-2, and is turned on in a substantially opposite relationship to the exposure lamp 23. 821 is a clutch that moves the mirror system for exposure scanning; 822 is a circuit for the exposure lamp 23; 823 is a circuit that turns off the fixing heater when an abnormality is detected in the machine; 824 is a clutch that turns on the cassette roller 11 or 12;
25 is a circuit for increasing the key counter, and 826 is a circuit for detecting a jam in the sorter 46, which outputs a jam signal when a sheet presses the switch 47 provided at the entrance of the sorter in Fig. 1 for a longer time than specified. . 827 is a mechanical latch relay that is set when the main body or sorter is jammed, and the sequence computer _Q101 reads the status of this relay through the _i4 port of _Q104 . By canceling this relay, the copy blocking state is canceled and the display 68
The number of jams lost is reset and displayed after subtracting the number of jams from the original number of copies.

This display 68 initially displays "01" and the number of inputs at the time of key input, and when copying starts, displays the number subtracted by one from that number each time paper is fed. At the final scan reversal, the original input number is displayed again to facilitate re-copying the same number. After 60 seconds, it returns to “01” again.

During copying, abnormalities in the forward and reverse clutches (the mirror does not reach the specified position at the specified time even though control output is performed), abnormalities in the drum clock pulse generator 818 (pulse intervals are longer than specified), temperature of the fixing heater The control thermistor may cause problems such as disconnection.
When detected by Q ₁₀₂ , numeric display 68 identifies the trouble. “E1”…”E3” errors are displayed. By repairing that part, the original number before switching is displayed.

Also, if the sorter ready signal is not obtained from the sorter 46, "E0" is similarly displayed. This display reset is also the same as above.

Also, when a jam occurs, the sequence computer
Sheet sensor 16 input to _i5 port of Q ₁₀₁ ,
18 sends jam data to Q ₁₀₂ via 809. Q ₁₀₂ determines the number of jam losses as 1 for the former and 2 for the latter, and displays them on the display 68 as "P1" and "P2". Similarly, “P0” is displayed during sortage jam.

In this example, reduced copying can be performed regardless of the cassette size, but it is not completely unrelated to the size detector 804, and is limited to only when reducing or equal size is selected.
Only when the size is not appropriate, the display 56 blinks to indicate the appropriate size. The sheet size that is being copied in parallel is also displayed. This has made it extremely safe to handle. Enlarged copying always scans B4 size strokes in consideration of the purpose of partial enlargement, so it is not displayed, but it is also possible to display whether it is appropriate or not.

Next, the display circuit 800 will be explained using FIG. 3-2. This circuit is a circuit diagram corresponding to the operation section 501 shown in FIG.

This circuit is connected to the DC controller board equipped with the microcomputer Q ₁₀₂ shown in Figure 3-1, and the key scan probe signal Digit
1 to 6, key scan output signal KEY0 to 3, dynamic display digit signal JD-1, 2,
4, 5, 6, and each terminal of dynamic display segment signals SEG-a to SEG-g is connected to _Q102 .

Furthermore, regarding the relationship _with FIG.
LEDs ₈₀₂ to ₈₀₈ and LEDs _{818 and 819} have the same names as the cassette size display 56 in FIG. 2, respectively. Light emitting diodes LED ₈₀₉ ~ LED ₈₁₅ are the second
Reduction, enlargement, same-size selection display in figures 60, 61, 62
Corresponds with the same name. However, M in FIG. 3-2 represents enlargement, and 1:1 represents equal magnification. Furthermore, the light emitting diodes LEDs _{816 and 817} correspond to the upper and lower stages of the cassette upper and lower stage selection display 72, respectively. These display blocking LDEs ₈₀₁ to ₈₁₉ are sequentially applied with a +24V power supply in a pulsed manner as each digit signal from JD-1 to JD-6 in the combination shown in the figure.
And as each segment signal from SEG-a to g,
Similarly, in the illustrated combination, a 0V power source is selectively applied to turn on the lights at the appropriate timing.

Operation time charts of Figures 4-1 to 4-2, Figures 6-1 to 6-4, and Figures 7-1 to 7
The control operation will be explained with reference to the control flowchart in Figure-6.

As a cycle executed prior to the above-mentioned copy cycle, there is a step of increasing the temperature of the fixing device after turning on the power switch SW1 while keeping the drum 1 and the fixing device 19 stopped. (Power switch on flow 70, 7 in Figures 4-1 and 7-1)
1) This is to prevent the toner from solidifying in the fixing device until the temperature of the fixing device rises to a certain level, which could damage the fixing roller 19, and to raise the temperature more efficiently. be.

Next, when the temperature of the fixing roller 19 exceeds the first set temperature, the main motor 21 is rotated at a low speed, and at the same time, the entire surface exposure lamp 9, the pre-exposure lamp 8,
The blank exposure lamp 10 is turned on to start irradiating the drum surface, and while the drum 1 rotates once, high voltage is applied to the secondary charger 4 and the light irradiation rotation continues until the second set temperature is reached. Yes (steps 72, 73). As a result, when the temperature of the fixing device exceeds the first set temperature, the toner is melted and will not damage the fixing roller 19, so the temperature distribution of the fixing device is made uniform, and the secondary charger 4 charges the drum 1.
The residual charge on the drum 1 is removed, the optical memory of the drum 1 is reduced by light irradiation rotation, and the drum surface is cleaned by a cleaner 6. In Figures 4-1 and 4-2, the dotted line in the main motor indicates low speed, and the solid line indicates high speed. It detects the opening and closing of the back door of the machine during a wait, and when it is opened, the wait lamp is turned off and a copy start command is input.

Further, until the temperature rises to the second set temperature, the lower fixing roller heater 32 is also turned on, contributing to the temperature rise.

Next, when the fixing roller reaches the second set temperature, the main motor 21 starts rotating at high speed.
High voltage is applied to the pre-static eliminator 2, primary charger 3, secondary charger 4, and transfer charger 5 at a value suitable for high-speed rotation, and the drum rotates once. It is called forward rotation (74,
75). This is to apply high pressure to the entire surface of the drum 1 after various high pressures have been applied. In addition, when switching the drum speed, the low speed signal to the main motor is turned off, and the Q ₁₀₁ outputs a high speed signal after 30 m seconds (73-2, 73-3). This prevents switching shocks.

At the same time, if the position of the lens 30 is not at the position 30-1 where the same-size copy is performed, the lens 30 starts moving to the same-size position (76).

Next, when the drum 1 completes one rotation, the drum surface potential (referred to as VSL) is measured by the potential sensor 44 with the blank exposure lamp turned on, and then the drum surface potential (referred to as VSL) is measured with the blank exposure lamp 10 turned off. Measure the surface potential (referred to as VD). The high voltage current flowing through the primary charger 3 and the secondary charger 4 is controlled by the values of VSL and VD so that it approaches predetermined VD and VSL. Repeat this control several times (77).

Next, when the position of the lens 30 has reached the same magnification position (30-1 in Fig. 1), the original exposure lamp 23 is turned on, and the standard white plate 35 is illuminated with a reflectance corresponding to the white background of the original. , the potential on drum 1 (VL
) is measured by the potential sensor 44.
By measuring VL, the density adjustment knob 54
At the "5" position, the lighting voltage of the original exposure lamp 23 is shifted so that an optimal image can be obtained. This VL measurement control is repeated several times to optimally control the shift amount of the lighting voltage of the document exposure lamp 23. Finally, VL is measured and the developing bias of the developing device 7 is set to the optimum value.

As described above, by measuring VSL, VD, and VL (collectively referred to as potential control), the amount of charge on the high-voltage drum 1, the light amount of the exposure lamp 23, and the developing bias are controlled, and the optimum image is obtained. It is configured so that it can be done. Then measure VL,
When the control ends, the wait ends and copying becomes possible (78).

Further, the drum 1 is rotated as a cycle after the control rotation or after the end of the copy rotation, and the secondary charger 4 removes residual charges and memory on the drum.
There is a step of cleaning the drum surface (hereinafter referred to as post-rotation). This is about 1/5 rotation using only the secondary charger 4, and about 1/2 rotation when the voltage applied to the secondary charger 4 is made weak. After the copy rotation is completed, the paper is rotated only by light irradiation until it is ejected.

The purpose of this post-rotation is to leave the drum 1 electrostatically and physically clean. After the post-rotation is completed, the drum stops, the fuser lower heater 32 lights up again, and the fixing roller is controlled by the thermistor 34 so that it is maintained at the third set temperature (see Fig. 7-5). steps, 570, 571).

After that, if the power switch is left for 2 hours without doing anything, the main SW2 will automatically turn off due to auto-shutoff.
Turned off (572).

If you operate each key before auto-shutoff,
The management computer sets each data.

When the copy key is pressed and the data is transferred to sequence Q ₁₀₁ , the preprocessing before starting the copy operation described above changes depending on the stop time (leaving time) of drum 1 and the variable magnification mode depending on the timing ( 573, 574).

The differences in this preprocessing are listed below.

(1) Leaving time 60 seconds or less If the variable magnification mode is changed, the developing bias must be changed by measuring VL.

If there is no change in magnification mode, there is no potential control.

(2) Standing time 60 seconds or more Control the optimum value of image formation by measuring VSL, VD, and VL.

After the above preprocessing is completed, the copying operation shown in FIGS. 7-1 B and C begins.

That is, even for variable size copying, if the start time is 60 seconds to 2 hours, the drum is operated at high speed in advance and then switched to low speed. Thereby, the above-described preparation process for the drum can be carried out sufficiently in a short period of time.

If the same size data or copy start command is sent from the management computer Q ₁₀₂ , the sequence computer Q ₁₀₁ determines it (via 78 and 79 when in B mode, and via 77 when in C mode). ,
Make the drum faster. Speed up the drum when changing magnification (reducing or enlarging). When changing the magnification (reducing or enlarging), the drum is delayed by 30ms and slowed down (80).
Next, as in step 81, the process is turned on and a lens movement permission signal is sent to the management controller _Q102 .
Q ₁₀₂ receives this and sets the lens at a desired position according to the control operation shown in FIG. 6-4. in this way,
Since the lens is set only after copying is started, no unnecessary lens operation is caused by changing the magnification. Therefore, abnormal noise caused by lens movement can be reduced.
Avoid shots as much as possible. In this example, this is also performed when an emergency copy is performed by interrupting copying, which will be described later, and when returning to the original copy mode after the copy is completed.

Also, when changing the magnification, the drum is rotated one more time (83).
This is for break-in operation when switching from high speed to low speed, and for potential stabilization and cleaning.

Management Q ₁₀₂ sets the lens position during previous rotation. Only when the lens is moved, the potential is measured and a predetermined developing bias is set (171). Next, the sequence Q ₁₀₁ requests the variable magnification mode data from the management Q ₁₀₂ , and if it determines that the data is an enlarged copy, it sends 3 as the scan reversal position data of the mirror system.
Data that is reversed at the middle position among the step positions
Set to RAM (172, 173). In other words, no matter what the cassette size is, the middle B4 size position is the stroke length.

In the first reduction mode (1:0.79), (173),
Requests size data of the selected cassette from management Q ₁₀₂ . Then, it is determined whether the cassette size is B5 (174), and if so, the short half-size position (A4) is set as reversal position data (175). If not, sequentially A4R, A4,
Determine whether B5R, u2 or not, and if they are different, set the longest full size position (A3) as inverted data (176). In either case, the original middle position is set. Note that u2 is a small set that can store various small size sheets such as postcards.

When in the second reduction mode (1:0.67) (177),
If it is not A4, B5, U2, or B5R, the full size will be used as the reversed data, and in any case, the middle position will be used.

At the same size, only A3 is full size, A4, A5,
Half size for any u2, medium size for others.

In this way, an appropriate reversal position can be determined depending on the variable magnification mode and the cassette at that time. This can prevent unnecessary scanning operations.

The above combination is shown in FIG. A double mark indicates that the variable magnification mode and cassette size are appropriate. FIG. 9 shows the direction and position of setting the document on the platen glass. The sheets are arranged in the cassette in the same relationship as this direction.

Next, in Figure 7-3, the counter for the number of sheets remaining in the machine, the total counter, and the key counter are incremented by 1 (271), it is determined whether the manual feed switch is on, and the operation control of the upper cassette roller is performed. Do (272). The stage data of the selected cassette from the management Q ₁₀₂ is determined and one of the rollers 11 and 12 is turned on (273). After that, turn off the solenoid that increases the key counter by 1. After a delay due to the count of the drum clock, a developing bias voltage is applied to the developing device, the blank lamp is turned off, and the document exposure lamp is turned on (274). The home position of the scanning optical system is confirmed (275), and a forward start signal for it is output (276).

At this time, one of the four advance clutches provided according to the variable magnification mode is selected, and the mirror and lamp are advanced at a scanning speed determined by the peripheral speed of the drum and the variable magnification ratio. 270mm/sec for actual magnification, 240mm/sec for 1:0.79 reduction, 284mm/sec for 1:0.67
seconds, 148mm/second when expanded. Outputs a signal to turn on the registration roller 15 during advancement (7-4
371) in the figure, it is determined whether or not the previously set inversion position has been reached by comparing it with the switch signal 815 in FIG. 3-1 (372). Then, turn on the blank lamp, turn off the forward movement of the mirror system, and turn on the reverse clutch (373). Then, the lamp is turned off or the exposure lamp is turned off with a delay only during reduction copying. The optical system reaches the home position and stops (470).

Then, each process is turned off and the aforementioned post-rotation routine is entered (570). Next, it is confirmed that the transfer paper is discharged from the switch 18, and the drum is stopped (571). Thereafter, the above-mentioned routine processing is performed depending on whether the input timing of the command data for restarting copying is within 60 seconds or not. If left unattended for more than 2 hours, the power of the microcomputer remains and everything else turns off.

Figure 7-6 is inserted into the closed loop of Figures 7-1 to 7-5, and the computer Q ₁₀₁
and Q ₁₀₂ , control to detect sheet ejection from sensor 18 and decrement the in-machine counter by 1, and control by inputting and determining the thermistor disconnection signal.
The control (I/O) sends abnormal data to Q ₁₀₂ , and the timer determines the forward/reverse clutch trouble.
Also, a timer is used to determine troubles in the drum clock pulse generator, and data transmission is similarly controlled. If a problem occurs, the process returns to the power switch determination routine shown in Figure 7-1 and waits.

Management Q ₁₀₂ receives this data and displays numerical display 6.
8 is marked with identification such as E1, E2, etc.

The main motor M1 is a motor that mainly drives the rotation of the photosensitive drum, fixing roller, etc. In this embodiment, the rotation direction of the motor is controlled so that the rotation speed of the drum is controlled in two stages. In the power transmission block diagram shown in Figure 5-1, one-way clutches CL1 and CL2 are provided on the output shaft of motor M1, and CL
2 is provided with a reduction gear. When the motor rotates clockwise (normal rotation), the power is directly output as clockwise rotational power via the one-way clutch CL1, that is, as shaft rotation along the normal rotation power transmission route LT1. Next, when the output shaft of motor M1 is rotated counterclockwise (reversely), at this time CL
1 does not transmit power; conversely, CL2 transmits power while the power is reversed, and is decelerated to a predetermined rotation speed by gear G1, and the output from G1 is again clockwise rotation, that is, when reverse rotation occurs. Along the power transmission route LT2, the rotation speed is reduced and output on the same axis as the above-mentioned shaft.

In this way, in this embodiment, the rotation speed is changed by switching the rotation of the motor M1 between forward and reverse directions. Thereby, the rotational speed (copying process speed) of the photosensitive drum can be changed at low cost and by simple control, and stable rotation can be obtained.

FIG. 5-2 shows another embodiment of speed switching. Motor 1-1 is a motor that has two outputs in the same rotational direction but with different rotational speeds, and the transmission of each is switched using electromagnetic clutches CL3 and CL4. There are several other methods that can be considered to simply switch the rotational speed. However, when these methods are limited to two-speed switching, they are the cheapest and have the highest reliability.

In Figure 3-3, in order to control speed switching with the main purpose of copying process speed, the common terminal J _11-1 of the main motor M1 is connected to one power source, and the main coil terminal J 11-2 is connected to the main coil terminal J _11-2 . Connect the phase advance capacitor C1 between the auxiliary coil terminal _J11-3 ,
In addition, terminals J _11-2 and J _11-3 are connected to the other power supply via solid state relays Q ₃₀₄ and Q ₃₀₅ , and Q ₃₀₄ is turned on to rotate M1 in the forward direction, and Q _{305 is}
is controlled to turn on M1 and reverse M1.

The operation of the management controller Q ₁₀₂ will be explained with reference to FIGS. 6-1 to 6-4. In Figure 6-1, when computer power is applied, the I/O port
The RAM is cleared to the initial state (step 60), the sequence controller Q ₁₀₁ confirms that reset has been completed (61), and operation begins. Then, an oscillator signal (1.2KHz) is applied to the interrupt terminal (iNT) to enable program interrupt processing (62).
An interrupt is generated by this signal, and the routine shown in Figure 6-2 is executed to perform the serial data transfer between the input scan of each KEY, the dynamic display of each display (162), and Q ₁₀₁ . Monitoring requests.

The probe signal for this dynamic display is used to detect an abnormality in the management controller _Q102 , so it is scanned and output regardless of whether the main switch is turned on or not, in preparation for display. But the main
When the SW is not turned on, the display power is turned off by the sequence controller Q ₁₀₁ , so it does not actually light up.

By the way, when a signal indicating that the main SW is turned on is transmitted from the sequence controller Q ₁₀₁ by serial transfer, the management controller Q ₁₀₂ allows key input, clears the two-hour timer, and restarts it (63-65).

During the wait, the sequence controller Q ₁₀₁ controls the current of the charger and the original exposure lamp by controlling the potential, so the lens position must be set to the same magnification position. Therefore, the management controller
Q ₁₀₂ receives a signal from the sequence controller Q ₁₀₁ requesting the "lens equal magnification position", so the lens is made equal magnified by the lens movement subroutine shown in FIG. 6-4 (67).

When the wait end signal is transmitted from the sequence controller by serial transfer, the 60 second timer is cleared and restarted (68).

By the way, the 2-hour timer and the 60-second timer are timers that are extended each time the operator operates the copying machine, such as by pressing a key. The 2-hour timer turns off the power switch to save energy when the operator forgets to turn off the power when the copier is not operated for more than 2 hours.
Make it. Further, the 60 second timer is used to initialize the display when the operator does not operate the copying machine for 60 seconds or more. This 60 second timer selects the standard mode, that is, the same size selection and the lower cassette, and sets the set number of copies (display 68) to "1" (69). However, if there is not enough developer or if there is no paper or cassette, the 60 second timer will not work.

This is done in consideration of the fact that the operator is recovering from a copy interruption state. Also, the 60 second timer does not operate while waiting.

MCOM-Q ₁₀₁ and Q ₁₀₂ in FIG. 3-1 will be explained in detail.

(Serial Transfer) Data exchange between microcomputers in this example is performed by data serial transfer. In this example, data is not transferred to either one of the two MCOMs, but simultaneously in both directions. The process will be explained in detail below using the flowcharts shown in FIGS. 6-2 and 7-6.

First, the sequence controller MCOM−
Management controller MCOM from port O ₁₁ on Q ₁₀₁
- Send a serial transfer request signal (RQ) to input port i ₁₁ of Q ₁₀₂ (step 600 in Figure 7-6). This is done by setting the serial request line i ₁₂ from Q ₁₀₁ to the "L" level. When Q ₁₀₂ senses the “L” level of this line i ₁₂ (step 164 in Figure 6-2), it prepares serial data from Q ₁₀₂ to Q ₁₀₁ (165) and can serially transfer it via line 111. Q ₁₀₁ signal (ENABLE) to the effect that
Send to (166). When Q ₁₀₁ receives this enable signal (602), it prepares for serial transfer data from Q ₁₀₁ (603), and then Q ₁₀₁ and Q ₁₀₂ simultaneously transfer data to each other and exchange data through lines 114 and 115, respectively. (Step 167 in Figure 6-2, Step 604 in Figure 7-6). In this step, it is determined whether the shift registers have received 16 bits of data, the data is stored in the RAM, and the contents are determined. The transfer is performed by sequentially shifting and storing data in each shift register using a shift clock pulse on line 113. As shown in FIG. 10, this data is set depending on whether the 16 bits are 1 or 0. Pipe → shi indicates the data content sent from Q ₁₀₂ to Q ₁₀₁ , and shi → pipe indicates the data content sent from Q ₁₀₁ to Q ₁₀₂ . For example, when Q ₁₀₁ receives and the data at address 1 of ST3 is 1,
Indicates that a problem has occurred with the lens movement when setting variable magnification. Sequence Q ₁₀₁ thereby inhibits the copy operation. When address 2 of ST1 is 1, it indicates input of an enlarged copy set. This allows Q ₁₀₁ to perform magnification control such as changing the speed of the main motor and optical system. Also, when _Q102 is received and address 2 of ST0 is 1, it indicates that a trouble has occurred in the movement of the optical system, etc. Management Q ₁₀₂ is
From this, error display (EO, etc.) and key input prohibition control are performed on the copy display 800 using LED segments. Also, when address 1,0 of ST0 is 1,
This indicates that the back door switch or main switch is open, and _Q102 changes the weight display or stops controlling the number display, etc. accordingly. Similarly, data written in the drawings corresponds to each bit.

The same applies when a sequence or transfer request is issued from the management Q ₁₀₂ port.

Q ₁₀₁ is configured to perform periodic serial transfer at approximately 370 msec. This is done by the transfer timer t (an internal timer as described above) (600, 606).

Also, monitoring of the serial request from Q ₁₀₂ in Q ₁₀₁ is performed by port sensing, and is performed by a subroutine provided in the closed loop routine in the main flow of the sequence. This subroutine also constantly monitors the on/off status of the main switch (step 599 in Figure 7-6).

Further, the monitoring of the serial request from Q ₁₀₁ in Q ₁₀₂ is subsequently performed within the dynamic control routine of key input control and display of the number of copies, etc. Therefore, it is monitored almost all the time.

By the way, the management controller Q ₁₀₂ has a timer t' that is initialized every time a serial transfer is performed, so that it can be checked if the serial transfer is stopped due to a runaway of the sequence controller Q ₁₀₁ or the like. That is, the internal timer is started at step 169 in Figure 6-2, and if the next transfer is not made within the timer time (170), the sequence controller recognizes that there is an abnormality and enters the closed loop program (172). , key scan, and segment scan probe signals are stopped. Thereby
The abnormality detection circuit 900 connected to Q ₁₀₂ is activated.
(Described later) The management controller abnormality detection circuit 900 is
Shown in Figure 2. This is a Digit for dynamic display of periodic signals output from the management controller _Q102 .
The signal is monitored, and if the digit signal does not change for a certain period of time, the reset circuit for microcontrollers Q ₁₀₁ and Q ₁₀₂ is activated. Therefore, if the sequence controller Q ₁₀₁ or the management controller Q ₁₀₂ is abnormal, the reset circuit causes the two microcomputers to run from the initial state of the flow.

(Computer reset control) When performing sequence control of a copying machine using multiple microcontrollers, the time it takes for the microcontrollers to reset and start running when the power is turned on may vary depending on the chip, and there is a possibility of copying errors. There is. In this example, when the reset of one microcontroller is completed (or after a certain period of time has elapsed after the reset is completed), it is checked whether the other microcontroller has been reset. This can prevent the microcomputer from running and the copying operation becoming uncertain.

In this way, after both microcomputers have been reset and are ready for operation, they start operating each other.

Also, if one MCOM is abnormal, the program will not run from that state, so both programs will not proceed. Therefore, the copier load does not operate unnecessarily.

Figure 6-1, flow diagram of Figure 7-1, 11th
This will be explained with reference to the circuit diagrams shown in FIGS.

When the line is connected to an AC outlet
The +5V power that operates the control center parts such as MCOM is turned on. Then, the reset circuit shown in FIG. 12 operates and MCOM-Q ₁₀₁ and Q ₁₀₂ are reset. Reset timer period MCOM−
The output ports of Q ₁₀₁ and Q ₁₀₂ are all at "H" level. Next, when the reset signal disappears, MCOM-
Q ₁₀₁ and Q ₁₀₂ start the program from address 0 in the ROM. MCOM-Q ₁₀₁ and Q ₁₀₂ each clear the RAM and set the output port to the initial state (60 in Figure 6-1, 60 in Figure 7-1)
68). Next, in order to eliminate mistakes in initial state exchange between MCOM-Q ₁₀₁ and Q ₁₀₂ , each of them consumes about 30 msec of time using an internal timer by counting the microcomputer clock. Then Q ₁₀₂ is
A serial transfer request (RQ) signal is output to _Q101 using output port O11. This output port is “H” at reset and in the initial state of the output port, and is “Low” when issuing a request.
It is structured to be level. MCOM−
Q ₁₀₁ detects that a serial request has been issued from Q ₁₀₂ and starts serial transfer. When the serial transfer is completed, MCOM-Q ₁₀₁ and Q ₁₀₂ check whether the serially transferred data is the data at the end of a predetermined reset (6th
61 in Figure-1, 69 in Figure 7-1) If there is an error in the transfer, retry the serial transfer. When the serial transfer data matches the predetermined data (address 3 of ST3 in Figure 10), the MCOM-
Q ₁₀₁ and Q ₁₀₂ enter the next operation.

(Power on/off control) Q ₁₀₁ monitors the main switch signal (70), and when the main switch is turned on, the main switch is turned on to Q _102.
Data is transferred by serial transfer to indicate that the SW has been turned on. Then, the 24V power supply used for loads such as the resist clutch and the 5V for display are turned on (70-1). While the main switch is not turned on, Q ₁₀₁ is
Wait while clearing RAM and I/O. This prevents malfunctions as much as possible.

In FIG. 11, the power-on signal is output from port O8 of Q ₁₀₁ and turns on the 24V power supply regulator VR1 and 5V regulator VR2 in the usual manner. Therefore display regulator VD2,
Even if the microcomputer regulator VR3 is connected to the transformer T2 rectifier D2 without going through a common main switch, the display can be reliably inactivated.

Furthermore, when resetting the microcomputer, a driving element such as a hammer driver conventionally connected to its output is turned on, and a voltage is applied to the load, causing the problem of turning on the load.

But after the microcomputer determines the output port status of all loads, the load power supply 24V
etc., so there is no inconvenience during a power-on reset. In addition, when a plurality of microcomputers are used, the risk can be prevented to the maximum extent because the program is run with the reset confirmation operation as described above.

Note that the reset confirmation may be performed for only one microcomputer (for managing the sequence).

(Computer Reset Circuit) Next, the microcomputer reset circuit shown in FIG. 12 will be explained. Q ₁₀₈ is a comparator with two circuits, and its functions are divided into Q _108-1 and Q _108-2 . First, when the microcomputer power supply +5V (Vcc) is turned on by turning on the power outlet or turning on the serviceman switch SW1 shown in Figure 3-3, each of the comparators Q _108-1 and Q _108-2 Resistance at the - side input terminal (No. 2) and + side input terminal (No. 5)
A voltage divided by approximately 1/2 of Vcc by RA _133-2 and RA _131-4 is applied as a threshold value. At this time, the rise of Vcc is delayed by a time constant circuit consisting of resistor RA _133-1 and capacitor C ₁₁₀ , and is applied to the + side input terminal (No. 3) of Q _108-1 via resistor RA _133-3 . Ru. At this time, for about 30 msec after the power is turned on, the voltage at the - side terminal is higher than the voltage at the + side terminal, and 0V is output from the output terminal (No. 1) of Q _108-1 , which is the reset signal for the microcontroller when the power is turned on. becomes. Note that diode D ₁₁₉ is a discharge diode when the power is turned off, and a resistor connected to terminals 3 and 1 of Q _108-1 .
RA _134-2 is designed to provide hysteresis to prevent malfunction and chattering. Also at this time Q _108-2
The output terminal (No. 7) is in the OFF state.

Next, to explain the microcomputer stop detection circuit, when MCOM-Q ₁₀₁ and Q ₁₀₂ are operating normally, a digit signal for dynamic display on the operation panel is output from MCOM-Q ₁₀₂ , and one of the signals is The part is further connected to the differential capacitor through the buffer driver Q ₁₁₂ as a repetitive pulse signal.
Trigger terminal (number 8) of timer ICQ ₁₃₅ via C ₁₀₆
is applied to At this time, the 8th terminal is resistor RA131
-2, a bias voltage of approximately 2.5V is applied by RA _131-3 , and the positive side clamp diode D ₁₂₁ is also connected as shown.

Time setting terminals 13 and 12 of this timer IC
The numbers include resistors RA _131-1 , RA _134-1 and capacitors.
_C107 , it is connected as shown in the figure so that the time-up time constant is longer than the interval of the minus trigger pulse inputted to the No. 8 terminal. When a trigger pulse is periodically input to this terminal No. 8, a voltage of approximately 5V is output from output terminal No. 9, and the input terminal ( ₁
At this time, the output terminal (No. 16) of Q ₁₁₉ is in the ON (0V) state.

On the other hand, the negative terminal (No. 6) of comparator Q _108-2
is connected to a time constant circuit composed of resistors R _134-4 and C ₁₁₅ , and the output terminal of Q ₁₁₉ is connected via R ₁₁₆ . When the power is turned on, the display digit signal is not generated until the microcontroller completes resetting, and 0V is output from the output terminal of Q ₁₃₅ , and the output of Q ₁₁₉ is in the OFF state _.
Terminal 6 gradually rises, but the voltage at terminal 6 becomes higher than that at terminal 5 after the power is turned on.
It is set as 330msec, and as mentioned above, during this time
Output terminal No. 7 of Q _108-2 is in the OFF state. However, by the time 330 msec has elapsed since the power was turned on, the microcontroller has completed its reset and started operating, so a display digit signal is generated, and the output terminal 16 of _Q119 turns on and becomes approximately 0V. For this reason Q _108-2
At the 6th terminal of Q, Vcc cannot rise above the voltage divided by R _134-4 and R ₁₁₆ , and by setting this divided voltage lower than the 5th terminal of Q _108-2 , In the end, Q _108-2 's output terminal No. 7 remains OFF, resulting in a steady state. If an abnormality occurs in the microcomputer and the display digit signal is no longer output, the output terminal 16 of Q ₁₁₆ will turn OFF.
As the voltage at the 6th terminal of Q _108-2 increases, the 7th output terminal of Q _108-2 will change after about 200 msec.
It becomes ON (approximately 0V), and by instantly discharging the charge of C ₁₁₀ , the voltage of the input terminal 3 of Q _108-1 is lowered, and the output terminal 1 turns ON (approximately 0V), and the reset signal of the microcontroller is sent. cause it to occur.

At this time, this reset signal is also applied as a "0" level to the trigger terminal (No. 8) of the timer ICQ ₁₃₅ via D ₁₂₀ as shown in the figure, and the output terminal No. 9 is
5V and the output terminal 7 of Q _108-2 is C ₁₁₅ , R ₁₁₆
After a slight delay due to the discharge time constant of This function is useful as an automatic repair function when the microcontroller itself malfunctions due to extreme external noise.

[Effects] As explained above, according to the present invention, if a transfer request signal for repeatedly transferring control data is not output within a predetermined time, an abnormality in the control means of the other party can be detected, and a special abnormality detection circuit is activated. There is no need to provide Moreover, the control means is not continued because the control means of the other party is not known to be abnormal.

Furthermore, by repeatedly transferring data, even if there is an error in the transferred data, the error can be corrected immediately.

[Brief explanation of drawings]

FIG. 1 is a sectional view of a copying apparatus to which the present invention can be applied, FIG. 2 is a plan view of the copying apparatus shown in FIG.
Figures 1, 3-2, and 3-3 are control circuit diagrams of the copying machine shown in Figure 1, and Figures 4-1 and 4-2 are control circuit diagrams of the
Figures -1 to 3-3 are input/output operation time charts, Figures 5-1 and 5-2 are main motor drive block diagrams, and Figures 6-1 to 6-4 are management computer. Control flowchart diagram No. 7-
Figures 1 to 7-6 are control flowcharts by the sequence computer, Figure 8 is a combination diagram showing suitability and unsuitability of the variable magnification selection mode and cassette size, and warnings, and Figure 9 is the copying machine shown in Figure 1. Figure 10 is a diagram showing serial transfer data, Figure 11 is a power supply circuit diagram, and Figure 12 is a reset circuit diagram. In the figure, 30-1 is at the same-size copy position. A certain lens, 1 is a photosensitive drum,
23 is an exposure lamp that scans, 24, 25
13 is an upper paper feed cassette, 14 is a lower paper feed cassette, and 46 is a sorter.

Claims (1)

[Scope of Claims] 1. An input means for inputting processing conditions, etc.; a process processing means for executing image formation; a first control means including a memory storing a control program for controlling the operation of the process processing means; a second control means including a memory storing a control program for controlling the first control means based on the image processing conditions inputted from the input means; A first plurality of control data including an abnormal state of the process processing means is transferred to a control means, and the second control means transmits a second plurality of control data indicating the image processing conditions to the first control means. In order to transfer data and repeatedly transfer the first or second plurality of control data, a transfer request signal is sent to the first and second plurality of control data.
is repeatedly output from one of the control means to the other at a predetermined period, and when the other control means detects that the next transfer request signal is not output within a predetermined time after receiving the transfer request signal, the one control means An image forming apparatus is characterized in that it determines that there is an abnormality and performs abnormality processing.